Device for the regeneration of a hydroconversion catalyst, hydroconversion method, and regeneration method

Abstract

The present invention relates to a method for the in situ regeneration of a hydroconversion catalyst. The invention also relates to a hydroconversion method comprising said regeneration method. The invention also relates to a system comprising a reaction section (40) comprising a hydroconversion reactor operating as a bubbling bed or a moving bed; a regeneration section comprising a regeneration device (100); means for transferring hydroconversion catalyst between the reaction section (40) and the regeneration section comprising at least one fluid connection; means for charging the regeneration device (100) in a fluidized bed or a moving bed.

Description

[0001] DEVICE FOR REGENERATION OF A HYDROCONVERSION CATALYST AND ASSOCIATED METHODS

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to a process for in situ regeneration of a hydroconversion catalyst. The invention also relates to a hydroconversion process comprising said regeneration process. The invention also relates to a system comprising a reaction section comprising a hydroconversion reactor operating in an ebullated bed or a moving bed; a regeneration section comprising a regeneration device; means for transferring hydroconversion catalyst between said reaction and regeneration sections comprising at least one fluid connection; means for loading said regeneration device in a fluidized bed or a moving bed.

[0004] Hydroconversion of residues is a process aimed at converting heavy feedstocks by exposing them to severe temperature conditions above 350°C, typically between 380 and 450°C in the presence of high pressure hydrogen, typically between 50 and 250 bars, in the presence of a solid catalyst containing metals such as Nickel or Molybdenum for example which are deposited on a support phase, often composed essentially of slightly acidic alumina and with porosity designed to allow the circulation of reactants and promote the deposition of coke and metals by limiting deactivation.

[0005] Under the temperature and pressure conditions of hydroconversion, the feedstocks will tend to form coke on the catalyst. A significant portion of the sulfur and nitrogen present in the feedstock is also deposited on the catalyst. The coke thus formed typically represents 5 to 50% by weight of the initial mass of catalyst depending on the operating conditions imposed, the feedstock and the catalyst. The content of coke deposited on the catalyst varies depending on the residence time of the catalyst in the reactor. The longer the residence time, the higher the content of coke deposited on the catalyst.

[0006] Conventionally, when the hydroconversion process is operated in an ebullated bed, a step / device for adding fresh catalyst and withdrawing spent catalyst makes it possible to compensate for the deactivation of the catalyst by regularly withdrawing and adding fresh catalysts. Catalyst regeneration technologies exist for refining processes such as, for example, reforming, which is used to upgrade a fraction of oil (heavy naphtha) into gasoline. A regenerative reforming process is known, using a circulating catalyst in a moving bed in several reforming reactors coupled to a regenerator. FCC or "fluid catalytic cracking", which is a process for converting heavy feedstocks such as atmospheric residues, using a circulating catalyst in a fluidized bed, also includes a regenerative technology.

[0007] There is currently no process for regenerating a used hydroconversion catalyst in situ. The used catalyst is generally disposed of or regenerated ex-situ, which requires transport, generally by truck, between the hydroconversion site and the regeneration site.

[0008] US Patent 4,621,069 describes a process in which a catalyst deactivated by the deposition of coke and sulfur compounds is continuously regenerated ex-situ by the staged combustion of coke and sulfur at controlled temperature in the presence of a gas stream containing a dilute concentration of oxygen. The catalyst is arranged in thin beds in equipment with multiple treatment zones.

[0009] Patent EP0378482 describes a method and device for regenerating the catalyst of a reforming process, comprising at least two reactors. The catalyst comprises a support and at least one noble metal from the platinum and chlorine family. In the regeneration process, the spent catalyst gradually moves from top to bottom in a regeneration chamber where it successively encounters: two moving bed zones where combustion takes place radially, then a moving bed oxychlorination zone and a calcination zone. Patent FR2837113 discloses in more detail the regeneration device used in the process of EP0378482. Patent EP0200474 also discloses the method for regenerating a reforming catalyst as well as the configuration of the regeneration device.

[0010] Patent EP0332536 discloses a process for the continuous regeneration of a catalyst, by fluidized bed combustion of the coke deposited on said catalyst during a hydrocarbon conversion reaction, this document discloses more particularly the regenerative technology of the FCC reactor. The FCC reactor connected to its regenerator operates in a regime where the phases present are gas and solid (catalyst), the feedstock to be converted is introduced in liquid form but it vaporizes instantly in the form of gas, the reactor therefore operates in a two-phase regime (gas-solid). In the FCC the catalyst is fluidized, that is to say in suspension in the gaseous phase. The present invention overcomes the lack of the prior art with the development by the applicant of a process allowing the regeneration of a hydroconversion catalyst in situ without leaving the hydroconversion installation.The regeneration process according to the invention also makes it possible to optimally improve the quality of regeneration by controlling the distribution of the regeneration gas flow over the entire catalyst grain bed. The loading and unloading steps of the regeneration section are well controlled using moving bed or fluidized bed flow technologies.

[0011] The regeneration method and system according to the invention comprise a regeneration device which makes it possible to regenerate the catalyst radially as do the regenerators used in regenerative reforming processes. This regeneration device differs from the devices of the prior art in that:

[0012] - it can be configured so that the catalyst is capable of being returned to the reaction section after a combustion step, thus the regenerator is devoid of a second combustion zone and / or an oxychlorination zone and / or a calcination zone and / or a reduction zone;

[0013] - it can be configured so that the catalyst can be transferred in a moving bed (by gravity) or in a fluidized bed, a fluidizing liquid being introduced into the device together with the addition of spent catalyst. The moving bed configuration makes it possible to load the catalyst very simply and quickly into the regenerator, in particular when the catalyst grains are spherical in shape. The fluidized bed configuration provides protection for the catalyst grains that are loaded into the regeneration device of the invention, in particular when they have complex shapes (multilobes for example). Fluidization also makes it possible to homogenize the catalyst grains which, after sedimentation and drainage of the fluidizing liquid, form a bed of homogeneous and better distributed catalyst grains within the device. The regeneration of the catalyst bed can then be carried out in an optimal manner.

[0014] The process for in situ regeneration of a spent hydroconversion catalyst according to the invention has the advantage of being able to be operated continuously, the additions and withdrawals of catalyst being carried out during the operation of the hydroconversion reactor(s) without it being necessary to stop the process. The regeneration process being integrated into the overall hydroconversion process, this makes it possible to regenerate the hydroconversion catalyst in situ according to the needs of the process. This also allows the operator to operate a single process in which he can manage the addition / withdrawal of regenerated catalyst according to the nature of the feedstocks treated and according to the addition of fresh catalyst and the withdrawal of spent catalyst. The regeneration process according to the invention thus makes it possible to reduce the consumption of fresh catalyst.

[0015] BRIEF DESCRIPTION OF THE FIGURES

[0016] Figure 1 illustrates the implementation of the hydroconversion process of the invention according to one embodiment. Only the main lines and equipment relating to the implementation of the catalyst and its regeneration are shown in this figure.

[0017] Figure 2 describes a regeneration device according to the invention making it possible to carry out regeneration of the catalyst by radial gas flow.

[0018] Figure 3 describes a particular embodiment of the bottom of the regeneration device according to the invention with a porous lower wall 11 1 of the second inclined enclosure allowing better evacuation of the regenerated catalyst.

[0019] DETAILED DESCRIPTION OF THE INVENTION

[0020] The description of the process is made with reference to figures 1, 2 and 3.

[0021] In the present description of the invention, the terms "catalyst", "hydroconversion catalyst" and "catalyst grains" are interchangeable.

[0022] Throughout this text, the terms "supply" or "inlet" and "outlet" or "discharge" and "in" or "out of" are used with reference to the direction of flow of fluids.

[0023] Regeneration process

[0024] The present invention relates to a method for in situ regeneration of a spent hydroconversion catalyst comprising the following steps: a) transferring the spent hydroconversion catalyst between a reaction section 40 comprising a hydroconversion reactor operating in an ebullated bed or a moving bed, preferably operating in an ebullated bed, and a regeneration section comprising a regeneration device 100; b) loading the regeneration device 100 with the spent hydroconversion catalyst; c) regenerating the spent hydroconversion catalyst within the regeneration device 100 and obtaining a regenerated hydroconversion catalyst; d) unloading the regenerated hydroconversion catalyst from the regeneration device 100; e) transferring the regenerated hydroconversion catalyst between the regeneration section and the reaction section 40;said reaction section 40 and regeneration section being connected to each other by at least one fluid connection allowing the transfers of the used hydroconversion catalyst and the regenerated hydroconversion catalyst.;

[0025] "Fluidic connection" means a conduit, circuit and / or possibly a capacity through which the hydroconversion catalyst is transported from a source to a destination by means of a liquid or air.

[0026] The catalyst used in hydrocarbon residue hydroconversion processes is deactivated by the combined effect of coke and metal deposition. It may then be advisable to take catalyst from the reaction zone 40, send it to a regeneration zone 100 dedicated to the controlled combustion of coke and sulfur, then once regeneration is complete, return it to the reaction zone 40.

[0027] The regeneration process according to the invention is particularly suitable for a hydroconversion process of a hydrocarbon feedstock with a low metal content. By low metal content is meant a metal content of between 5 ppm by weight and 150 ppm by weight, even more preferably between 10 and 75 ppm by weight. For these feedstocks, the coke content deposited on the catalyst increases faster than the metal content deposited, hence the advantage of the regeneration process according to the invention.

[0028] The metal content is for example evaluated according to the ASTM D8252 method which indicates the Nickel and Vanadium content “(Ni+V)” in ppm by weight.

[0029] The regeneration process according to the invention may be a continuous catalyst regeneration process or operated sequentially. The catalyst transfers between the reaction section and the regeneration section are carried out regularly during the operation of the hydroconversion process without stopping it. The regeneration device in its operating mode preferably operates sequentially. The coke combustion phases are preceded or followed by the steps of loading, unloading, drying and inerting the catalyst and possibly sedimentation steps when the transfer is carried out in a fluidized bed. All these steps are preferably carried out within the regeneration device 100. Step a) of transfer between the reaction section and the regeneration section

[0030] According to the invention, the regeneration process comprises a step a) of transferring the used hydroconversion catalyst between a reaction section 40 comprising a hydroconversion reactor operating in an ebullated bed or in a moving bed, preferably in an ebullated bed, and a regeneration section comprising a regeneration device 100.

[0031] The reaction section 40 of step a) may advantageously comprise one or more reactors in which a hydroconversion reaction takes place in the presence of a catalyst from the moment that an operation of withdrawing one or all part of the catalyst is feasible, for example a hydroconversion reactor operating in an ebullated bed (preferred mode) as well as possibly in a moving bed.

[0032] Hydroconversion reactors are three-phase (gas-liquid-solid) reactors. They generally operate at high pressure to promote hydrogenation, and the feedstocks treated are in the liquid state. The liquid phase is therefore essentially the hydrocarbon fraction, the gaseous phase is the hydrogen and the converted light gaseous fractions, and the solid phase is the catalyst. The gaseous phase is a minority and flows into the liquid phase.

[0033] In the ebullated bed hydroconversion reactor (also called a three-phase fluidized bed), the gas and liquid flow axially in an upward motion. The liquid velocity is higher than the minimum fluidization velocity of the catalyst (which also depends on the gas flow rate). The catalyst is free to move in the reactor and circulates inside a dense phase consisting of the liquid and the gas. The catalyst is introduced at one point and withdrawn at another point in the dense phase.

[0034] Examples of hydroconversion reactors operating in an ebullated bed are the H-OIL® from Axens or LC FINING® from Lummus.

[0035] In the moving bed hydroconversion reactor, the catalyst is introduced into the upper part of the reactor and flows axially from the top of the reactor to the bottom under the effect of gravity grain by grain. Liquids and gases flow either axially from the top to the bottom or from the bottom to the top of the reactor.

[0036] An example of a hydroconversion reactor operating in a moving bed is the Shell HYCON® reactor. The regeneration section 100 may comprise one or more regeneration devices according to the invention.

[0037] In one embodiment, the regeneration method according to the invention is characterized in that the hydroconversion reaction section 40 comprises at least one, two or three hydroconversion reactors operating in an ebullated bed.

[0038] In one embodiment, the transfer of the spent hydroconversion catalyst between the reaction section 40 and the regeneration section is carried out by liquid phase conveying.

[0039] When the conveying is carried out in the liquid phase, the person skilled in the art knows how to determine the nature and flow rate of liquid necessary to achieve sufficient fluidization of the catalyst and allow its transport from one capacity to another. It is well known to the person skilled in the art to implement gentle fluidization in order to avoid shocks between the catalyst grains while respecting a fluid speed higher than but close to the minimum fluidization speed of the catalyst.

[0040] Step b) loading the regeneration device

[0041] According to the invention, the regeneration method comprises a step b) of loading the regeneration device 100 with the used hydroconversion catalyst.

[0042] In one embodiment, the regeneration section comprises a loading pot 70 containing the spent hydroconversion catalyst awaiting regeneration, and the step of loading the regeneration device 100 with the spent hydroconversion catalyst comprises a step of transferring said spent hydroconversion catalyst between said loading pot 70 and said regeneration device 100. In this embodiment, the opening 9 of the regeneration device 100 allowing the entry of the spent catalyst into said device is in fluid connection with a loading pot 70 via a substantially vertical conduit, preferably having a deviation from the vertical of less than 25° to allow a gravity flow between these two capacities. An isolation valve is preferably positioned on this conduit. Preferably, the opening allowing the entry of the spent catalyst is positioned in the center of the regeneration device.

[0043] In one embodiment, the loading pot 70 is equipped with a device for measuring the quantity of spent hydroconversion catalyst present therein. For example, the measurement can be carried out with devices combining pressure measurements, using acoustic waves or radioactive rays.

[0044] The loading of the catalyst into the regeneration device can be carried out in a moving bed or preferably in a fluidized bed.

[0045] In one embodiment, the step of loading the regeneration device 100 with the spent hydroconversion catalyst is carried out in a fluidized bed. In this embodiment, a fluid, preferably a liquid, passes through the regeneration device with a substantially vertical upward movement to allow the catalyst to be regenerated to be fluidized in the regeneration device. The catalyst preferably flows by gravity and arrives in said fluid. The fluidization makes it possible to improve the distribution of the catalyst.

[0046] In a preferred embodiment, the step of loading the regeneration device 100 with the spent hydroconversion catalyst is carried out in a fluidized bed with a fluidizing liquid.

[0047] When the loading of the device is carried out in a fluidized bed, the catalyst present in the loading pot 70 is preferably also fluidized and flows into the regeneration device with a part of the fluidization liquid, the other part of the fluidization liquid always being introduced from the bottom of the regeneration device in an upward movement.

[0048] In one embodiment, when the loading of the regeneration device 100 with the spent hydroconversion catalyst is carried out in a fluidized bed, the regeneration method further comprises a step of draining the fluidization liquid and a step of drying the spent hydroconversion catalyst prior to the step of regenerating said spent hydroconversion catalyst. The same applies when the transfer between the reaction section 40 and the regeneration section is carried out by conveying in the liquid phase and the device 100 is loaded in a moving bed.

[0049] When the regeneration device is loaded with a fluidized bed, a liquid is introduced through the opening 101 of the first enclosure of the regeneration device 100 and distributed into the second enclosure 107 by means of its porous lower wall 11 1. The upward velocity of the liquid in the annular passage section of the second enclosure 107 around the conduit 109 is greater than the minimum fluidization velocity of the catalyst. The liquid introduced through the opening 101 and the liquid introduced with the catalyst through the opening 9 exit the regeneration device 100 through the opening 102. During this phase, the other openings of the regeneration device are kept closed. Once the desired quantity of catalyst has been introduced into the device, the supply of liquid through the openings 101 and 9 is interrupted.

[0050] The term "minimum fluidization velocity" refers to the minimum velocity at which the fluid must pass through the catalyst grain bed to allow the grains to be suspended within the fluid. Under these conditions, the pressure drop of the fluid passing through the catalyst grain bed corresponds to the weight of the bed.

[0051] This fluidized bed loading method is particularly suitable for processes using complex-shaped catalyst grains (substantially non-spherical) such as extrudates or multi-lobe catalysts, whose granular flow characteristics are more delicate and limited due to their shape. This operating mode limits the mechanical degradation of the catalyst by attrition. By fluidizing the catalyst grains under gentle conditions (the fluidization speed being close to the minimum fluidization speed), any risk of flow blockage is avoided. In addition, at the end of loading, when the catalyst grain bed settles by stopping the fluidization, a homogeneous loading density throughout the device is obtained as well as a uniform level of catalyst.The use of a liquid also allows for homogeneous expansion of the bed without bubbles, which limits attrition of the catalyst grains.

[0052] Preferably, during fluidization, the superficial velocity of the fluid in the catalyst grain bed is 2 to 5 times the minimum fluidization velocity of the catalyst particles.

[0053] Preferably, the fluid used to fluidize the catalyst bed is a light petroleum fraction sufficiently viscous to promote fluidization of the catalyst. Preferably, said fluid is chosen from a fraction with a boiling range between 150 and 380°C, for example a hydrocarbon fraction of the kerosene and / or diesel type.

[0054] Once the desired quantity of catalyst grains has been introduced into the regeneration device 100 (for example when the loading pot 70 is empty), the supply of fluidization liquid is interrupted. The catalyst grains then sediment naturally. The sedimentation makes it possible to naturally obtain a distribution of the catalyst grains forming a homogeneous bed having a substantially horizontal and uniform level over the entire section of the second enclosure 107. In one embodiment, the second enclosure of the regeneration device comprises an empty space 115 located above the bed of catalyst grains when it is loaded with sedimented catalyst grains. This space is intended for the steps of transferring the catalyst into a fluidized bed.Indeed, when the catalyst grain bed is fluidized during unloading, it will undergo a volume expansion which must be contained in the volume of the second enclosure 107 in order to avoid any overflow of the bed through one of the openings 102 or 9 while allowing the fluidization to be optimal.

[0055] Preferably, the volume of the empty space 115 makes it possible to absorb a volume expansion of between 10 and 100% of the volume of the catalyst grain bed after loading and sedimentation, preferably between 25 and 50% of this volume.

[0056] Once the catalyst grains have settled, the fluidization liquid must be evacuated by draining all the parts constituting the regeneration device. All the openings 102, 9, 101 and 10, 14 and 15 of the device can allow the fluidization liquid to be drained.

[0057] Once the drainage step has been completed, a catalyst drying step must be carried out. During the drying step, an inert drying gas such as nitrogen is introduced into the regeneration device through the openings 14, 9 or 102 and then exits through the central conduit 109, the other openings being closed. This inert gas is advantageously heated upstream of the regeneration device 100 to a temperature of between 250° and 400°C depending on the liquid used during loading to allow its evaporation. The drying gas containing the evaporated hydrocarbons is then advantageously cooled to condense the hydrocarbons, then is advantageously reheated and recompressed to then be reintroduced into the regeneration device.

[0058] The drainage and drying steps help to minimize the quantities of coke present on the spent catalyst grains which will then be burned during the combustion regeneration phase.

[0059] At the end of the drying stage, the catalyst can be regenerated.

[0060] In one embodiment, the step of loading the regeneration device 100 with the spent hydroconversion catalyst is carried out in a moving bed. In this embodiment, the catalyst is not fluidized during catalyst loading but is loaded by gravity flow into said regeneration device, in this case the catalyst introduced through the opening 9 flows by gravity into the second enclosure 107 of the device. This embodiment is ideally implemented when the hydroconversion catalysts are spherical in shape. Moving bed transfers are well known to those skilled in the art for spherical catalysts. This involves transferring by gravity between the equipment when possible. When gravity transfer is not possible, if the inlet capacity is located higher, those skilled in the art can use a flow of inert gas to raise the catalyst.The gas flow is then divided into two conduits: the first allows a quantity of catalyst to be fluidized in a dedicated capacity. The second flow then allows the quantity of catalyst to be set in motion in a tube heading towards the inlet capacity. The catalyst then flows without the surrounding environment being fluidized.

[0061] When moving bed transfer is implemented, the sedimentation, drainage and drying steps are not necessary. In addition, there is no need to provide an empty space 1 15 located above the catalyst grain bed.

[0062] Step c) regeneration of the used catalyst

[0063] According to the invention, the regeneration method comprises a step c) of regenerating the used hydroconversion catalyst within the regeneration device 100 and obtaining a regenerated hydroconversion catalyst.

[0064] In one embodiment, the regeneration comprises a step of combustion of the coke and sulfur compounds of the spent hydroconversion catalyst, carried out with a gas flow comprising oxygen passing through said spent hydroconversion catalyst radially within the regeneration device 100.

[0065] In one embodiment, the regenerated hydroconversion catalyst is preferably free of the majority of the coke it initially contained, preferably free of 80% by weight of the amount of coke initially contained, more preferably 90%, or even 100% of the amount initially contained, and can then be reused depending on the needs of the operation of the hydroconversion reaction zone.

[0066] Preferably, once the spent catalyst is loaded into the regeneration device 100, the level of the spent catalyst should be higher than the highest part of the porous section of the side walls 105 and 108 of the second enclosure of the device. Thus, the height of the catalyst grain bed located above the porous section of the second enclosure 107 will provide resistance to the flow of gases above the catalyst bed during the drying, purging or regeneration phases. Indeed, the gases flowing radially could bypass the catalyst grain bed by flowing into the space left free above the bed and impair the performance of the system.

[0067] The step of regenerating the spent catalyst is carried out by circulating the combustion gases radially in the catalyst bed, in a substantially horizontal direction and preferably directed from the outside towards the inside of the regeneration device 100. This makes it possible to optimize the good distribution of the oxidant in the regenerator and therefore to have good uniform contact between the oxidant (combustion gas) and the fuel (coke present on the spent catalyst grains) during regeneration and to avoid hot spots and preferential passages which would induce poor regeneration or hydrothermal degradation of the catalyst.

[0068] By "radially" is meant that the gases pass through the second enclosure 107 of the regeneration device 100 through the porous parts of the side walls 105 perpendicular to the vertical axis of the device, the gases therefore pass through the catalyst bed perpendicular to the vertical axis of the bed. In this arrangement, the catalyst forms a layer distributed around the central collector formed by the third enclosure 109, in which the regeneration gases are distributed uniformly. In this device, the regeneration of the catalyst is therefore of good quality.

[0069] In one embodiment, the device is configured so that a first portion of the regeneration gases, preferably the majority of the regeneration gases, or at least 70%, preferably at least 80% of the regeneration gases, passes through the bed of catalyst grains radially. This portion of the gases is advantageously introduced through the opening 14 into the first enclosure of the regeneration device 100 which spreads into the first empty upper zone 103; 104 of said device.

[0070] In this implementation, preferably, the remaining part of the gases which are not introduced into the device through the opening 14, enters the second enclosure 107 through the top, for example through the opening 9, or through the base of the catalyst grain bed for example through the opening 101 where the gas spreads into the second empty lower zone 112 located between the first and second enclosures and passes through the porous lower wall 111 of the second enclosure and mixes with the regeneration gases mainly introduced through the opening 14. In one embodiment, the empty lower zone 112 is preferably slightly overpressured relative to the lower zone of the catalyst grain bed contained in the second enclosure 107. This is achieved for example by injecting small quantities of gas through the opening 101.Thanks to the pressure drop offered by the passage of this gas through the porous lower wall 1 11 of the second enclosure, the empty space 1 12 is then under overpressure relative to the bed of catalyst grains, which limits the passage of gas from the bed of catalyst grains to the empty lower zone 1 12.

[0071] Introducing said remaining portion of the gases into the regeneration device 100 via the base or the top of the catalyst grain bed makes it possible, on the one hand, to regenerate the catalyst grains located above the top of the porous portions of the side walls 105 and 108, and, on the other hand, to prevent gas passing through the bed radially from bypassing it by circulating in the empty space 115 located above the bed or in the empty lower zone 112 located below the porous lower wall 111 of the second enclosure. In fact, the regeneration gases tend to flow through the zones offering the least resistance to flow and therefore offering a lower pressure drop. By increasing the resistance to flow in the empty spaces 115 and 112, the radial flow of the regeneration gases passing through the catalyst grain bed is therefore optimized.

[0072] The presence of one or more plates 113 within the second enclosure 107 of the regeneration device 100 makes it possible to increase the resistance to the flow of gases in the empty space 115. Preferably, the upper part of the plate(s) 113 emerges above the bed of catalyst grains in the empty space 115 of the second enclosure 107.

[0073] Preferably, the radial velocity of the gases during the regeneration phase at the inlet of the catalyst bed at the periphery is between 0.02 and 0.5 m / s.

[0074] Preferably, the radial velocity under the same conditions but at the outlet of the catalyst bed will preferably be between 0.25 and 2.5 m / s.

[0075] In one embodiment, the opening 14 for admitting the regeneration gases into the regeneration device 100 is in fluid connection with a gas circuit making it possible to partially recycle the gases entering said device. An isolation valve is preferably positioned on this conduit. Preferably, this opening is also used if necessary for introducing into the device the gases making it possible to dry the catalyst grain bed after loading and to purge the device. In one embodiment, the opening 15 which allows the evacuation of the combustion fumes resulting from the regeneration of the catalyst grain bed as well as the gases resulting from the drying of the catalyst grain bed after loading and purging of the regeneration device 100 is connected to the gas circuit making it possible to partially recycle the gases entering the reactor through the opening 14.An isolation valve is preferably positioned on this conduit.

[0076] The combustion step of coke and sulfur compounds is preferably carried out in a controlled combustion step in the presence of oxygen.

[0077] On the one hand, the combustion step is implemented by limiting the oxygen concentration available in the gas at the inlet of the regeneration device to a content preferably between 0.1 and 5% by volume. This makes it possible to control the contact conditions between the fuels deposited on the catalyst grains (coke, sulfur, nitrogen) and the oxidizer (oxygen contained in the regeneration gas) in order to avoid degradation of the properties of the catalyst grains. Indeed, the catalyst grains are sensitive to hydrothermal deactivation associated with the presence of high-temperature water vapor.

[0078] In one embodiment, the combustion gas comprises a controlled oxygen content, typically between 0.1% and 5%, preferably between 0.3% and 1%.

[0079] On the other hand, the combustion stage is implemented by controlling the gas distribution so that the flow is as uniform as possible in contact with the catalyst grains.

[0080] In one embodiment, the combustion gas is preheated to a temperature between 250 and 600°C, preferably between 275°C and 500°C.

[0081] As the combustion step is implemented by limiting the oxygen supply, this makes it possible to control the progress of the combustion reactions and therefore to limit the increase in temperature. The temperature of the gas at the inlet of the regeneration device is therefore gradually increased while limiting the temperature gradient in the combustion zone in order to limit the temperature at the outlet of the device below a value generally between 350 and 600°C depending on the nature of the catalyst grains to be regenerated.

[0082] In one embodiment, the regeneration is carried out in increasing temperature steps, limiting the heating of the catalyst bed to a temperature gradient of between 10 and 100°C, preferably between 25 and 50°C. When the outlet temperature values ​​and the oxygen concentration values ​​of the outgoing combustion gas approach the values ​​characterizing the inlet gas, it is possible to increase the temperature of the inlet gas. The combustion step is typically completed when no more heating or oxygen consumption is observed at the maximum inlet gas temperature permissible for the catalyst grains.

[0083] In one embodiment, a portion of the regeneration fumes leaving the regeneration device 100 can be recycled to the inlet of the device after a washing and / or purification step to be freed at least in part from the sulfur and nitrogen oxides resulting from the combustion of the coke, for example by contact with an aqueous sodium solution and after a compression step to compensate for the pressure drop.

[0084] In one embodiment, at least one or more charge-effluent exchangers make it possible to preheat the combustion gas with at least part or even all of the combustion fumes exiting at a higher temperature and possibly with external heat sources.

[0085] In one embodiment, before recycling the combustion fumes after washing or purification, a fresh air supplement is provided to allow regeneration, an inert gas supplement is provided to allow drying or inerting, preferably nitrogen, and the fumes are purged, as well as a bypass to an exchange system to condense any hydrocarbons produced during the intermediate phases of drying the catalyst between the loading of the reactor in the liquid phase and the regeneration which takes place in the gas phase.

[0086] The time required for regeneration is related to the quantity and composition of the coke deposited on the catalyst as well as the oxygen concentration chosen to control the regeneration conditions and limit heating of the catalyst grains. Typically, it is possible to regenerate the catalyst grains by burning 80% to 100% of the coke deposited on the grains in less than 96 hours, preferably between 48 and 72 hours, while limiting the temperature difference between the regeneration inlet and outlet below 50°C.

[0087] In one embodiment, the regeneration step c) further comprises a step of inerting the regenerated hydroconversion catalyst before unloading the regeneration device. This step is carried out by circulating an inert gas such as nitrogen, for example, throughout all the parts constituting the device. In one embodiment, the bed of catalyst grains is cooled to a temperature below 300°C, preferably below 100°C, before unloading the grains.

[0088] Preferably, at the end of the regeneration step c), the regenerated catalyst free from the majority of the coke deposited during the hydroconversion recovers most of its catalytic activity allowing it to desulfurize and demetallize the hydroconverted hydrocarbons.

[0089] Step d) unloading the regenerated hydroconversion catalyst

[0090] According to the invention, the regeneration method comprises a step d) of unloading the regenerated hydroconversion catalyst from the regeneration device 100.

[0091] In one embodiment, the regeneration section further comprises a storage enclosure for the regenerated hydroconversion catalyst 80 and the step of unloading the regenerated hydroconversion catalyst from the regeneration device 100 comprises a step of transferring said regenerated hydroconversion catalyst between said regeneration device 100 and said storage enclosure 80. In this embodiment, the at least one opening 10 of the regeneration device allowing the catalyst grains to exit after regeneration is in fluid connection at one end with the interior of the second enclosure 107 and at the other end with a storage enclosure 80 for the regenerated hydroconversion catalyst. An isolation valve is preferably positioned on this conduit. Preferably, the volume of the conduit located upstream of the isolation valve is minimized. Preferably, the fluid connection is substantially vertical.

[0092] The unloading of the catalyst grains is carried out in a moving bed or in a fluidized bed, preferably in a fluidized bed.

[0093] In a preferred embodiment, the unloading of the catalyst from the regeneration device is carried out in a fluidized bed. In this embodiment, a fluid, preferably a liquid, passes through the regeneration device 100 with a substantially vertical upward movement to allow the regenerated catalyst to be fluidized in the regeneration device and transported through the at least one opening 10. The fluidization of the catalyst during the unloading of the regeneration device makes it possible to facilitate the flow and to avoid any blockage of the catalyst in the regeneration device. In this case, a liquid is introduced through the opening 101 of the regeneration device 100 and distributed in the second enclosure 107 thanks to the porous lower wall 11 1. The liquid passes through the bed of catalyst grains axially from the bottom of the device upwards, which will allow rapid unloading of the regenerated catalyst grains.

[0094] In one embodiment, the opening 102 of the regeneration device for evacuating the excess liquid used to fluidize the catalyst grains is in fluid connection with a circuit for evacuating said fluid during the loading and unloading phases. An isolation valve is preferably positioned on this conduit.

[0095] The opening 10 of the regeneration device allows the gravity flow of the mixture comprising the catalyst grains and a portion of the fluidization liquid, once the catalyst grains have been fluidized. During fluidization and unloading, the other openings of the regeneration device are closed.

[0096] When the lower wall 1 11 of the second enclosure of the regeneration device is conical in shape pointing towards the bottom of the device, the unloading of the catalyst is carried out more easily. The inclined lower part 11 1 facilitates the evacuation of the catalyst through the opening 10, even in the event of a problem linked to fluidization problems such as partial blockage of the lower wall 1 11.

[0097] In one embodiment, the catalyst grains fluidized during unloading flow by gravity, with possible pressurization upstream, into the opening 10 and are then taken up by means allowing their transport, possibly to the storage enclosure 80, such as for example an injection of transport liquid allowing transport in suspension in pipes sized for this purpose.

[0098] In one embodiment, an isolation valve is preferably positioned on the conduit connected to the opening 101 allowing the introduction of the fluid allowing the fluidization of the catalyst grains during the loading and / or unloading of the regeneration device.

[0099] In one embodiment, the unloading of the catalyst from the regeneration device is carried out in a moving bed by gravity flow of the catalyst through the at least one opening 10 of the regeneration device 100. In this case, the catalyst grains flow by gravity through the opening 10 without being fluidized in the second enclosure 107, or else a liquid can still be introduced with a speed lower than the fluidization speed of the catalyst grains, only making it possible to facilitate the natural flow of the catalyst grains through the conduit 101. This embodiment can be envisaged when the gravity flow of the particles is easy, for example when the particles have a substantially spherical shape.

[0100] When unloading is carried out in a moving bed, the opening 10 allowing the regenerated catalyst to exit is positioned in the center of the regeneration device for the single opening or on a circular crown if there are several openings.

[0101] In this embodiment, the catalyst grains flow by gravity during unloading either to an intermediate buffer enclosure (not shown) or directly to the regenerated hydroconversion catalyst storage enclosure 80. If necessary, they can be recovered by means allowing their transport to said storage enclosure 80, such as for example an injection of transport liquid allowing transport in suspension in pipes sized for this purpose.

[0102] Step e) transfer between the regeneration section and the reaction section

[0103] According to the invention, the regeneration process comprises a step e) of transferring the regenerated hydroconversion catalyst between the regeneration section and the reaction section 40.

[0104] In one embodiment, the transfer of the regenerated hydroconversion catalyst between the regeneration section and the reaction section 40 is carried out by liquid phase conveying.

[0105] Hydroconversion process

[0106] The present invention also relates to a hydroconversion process comprising the following steps:

[0107] I. a step of hydroconversion of a hydrocarbon feedstock having an initial boiling point of at least 300°C carried out in a reaction section 40 comprising a reactor operating in an ebullated bed or in a moving bed in the presence of a hydroconversion catalyst and hydrogen;

[0108] II. a step of withdrawing spent hydroconversion catalyst and adding fresh hydroconversion catalyst from a storage enclosure 20 for fresh catalyst and / or hydroconversion catalyst regenerated according to the regeneration method according to the invention within said reaction section 40. Step i. of hydroconversion

[0109] The hydroconversion process according to the invention comprises a step i. of hydroconversion of a hydrocarbon feedstock having an initial boiling point of at least 300°C carried out in a reaction section 40 comprising a reactor operating in an ebullated bed or in a moving bed in the presence of a hydroconversion catalyst and hydrogen.

[0110] In a preferred embodiment, the hydroconversion step is carried out in one or more ebullated bed reactors, particularly two or three ebullated bed reactors. This type of reaction section allows for good temperature control within the reaction zone. The reaction zone of an ebullated bed process generally consists of one or more reactor trains containing one or more reactors in series.

[0111] In one embodiment, the hydroconversion step is carried out under an absolute pressure of between 2 and 35 MPa.

[0112] In one embodiment, the hydroconversion step is carried out at a temperature between 300 and 550°C.

[0113] In one embodiment, the hydroconversion step is carried out at an hourly space velocity (or WH for Hourly Volumetric Velocity) of between 0.05 h -1 and 10 a.m. 1 .

[0114] In one embodiment, the hydroconversion step is carried out under a quantity of hydrogen mixed with the feedstock of between 50 and 5000 normal cubic meters (Nm 3 ) per cubic meter (m 3 ) of liquid charge.

[0115] In one embodiment, the hydroconversion step is carried out with a porous supported catalyst comprising an alumina support and at least one group VIII metal chosen from nickel and cobalt, said group VIII element being used in association with at least one group VIB metal chosen from molybdenum and tungsten.

[0116] In ebullated bed hydroconversion processes, the catalyst is generally used in the form of extrudates whose diameter generally varies between 0.5 and 3 mm, the length of the extrudate generally corresponding to a length ranging from 1.5 to 10 times the grain diameter. Forming into beads of similar diameter or multilobe particles, whose average characteristic sizes are similar, is also possible.

[0117] The feedstock of the hydroconversion process according to the invention preferably comprises so-called heavy hydrocarbons having an initial boiling point of at least 300°C.

[0118] The feedstocks converted in this type of process are generally heavy feedstocks characterized by their boiling curve and are generally feedstocks of which less than 5% distils under atmospheric conditions at a temperature of 340°C. The process is particularly suitable for the conversion of feedstocks containing at least 60% of feedstock distilling above 500°C. These feedstocks are characterized by high sulfur, nitrogen and metal contents, which are mostly removed during the hydroconversion reactions.

[0119] Typically, a feedstock heavily loaded with metals will contain in the order of 50 to 500 ppm, generally essentially nickel and vanadium which, during the hydroconversion reactions, will be deposited on the catalyst, the quantities of metals deposited typically being able to reach from 5% to 50% by weight of the initial mass of the catalyst. The regeneration process according to the invention is particularly suitable for a heavy hydrocarbon feedstock with a metal content of between 5 ppm by weight and 150 ppm by weight, even more preferably between 10 and 75 ppm by weight.

[0120] The said charge may be of petroleum origin of atmospheric residue type or vacuum residue from so-called conventional crude (API degree > 20°), heavy (API degree between 10 and 20°) or extra heavy (API degree < 10°) or crude oil. It may come from different geographical and geochemical origins (type I, II, IIS or III), with different degrees of maturity and biodegradation.

[0121] This feedstock can also be chosen from the following feedstocks: a residual fraction from the direct liquefaction of coal (atmospheric residue or vacuum residue from, for example, the H-Coal™ process), an H-Coal™ vacuum distillate, a residual fraction from the direct liquefaction of lignocellulosic biomass alone or in a mixture. These feedstocks can be mixed with coal and / or a residual petroleum fraction.

[0122] This type of feedstock is generally rich in impurities with metal levels of at least 5 ppm by weight, in particular at least 10 ppm by weight, typically in the order of 10 to 500 ppm by weight in metals, essentially Nickel and Vanadium. The sulfur content is typically at least 0.5%, in particular at least 1%, in particular greater than 2% by weight. The C7 asphaltene level is in particular greater than 1%, in particular between 1 and 40% and more preferably between 2 and 30% by weight.

[0123] Step ii. withdrawal of the used catalyst and addition of fresh catalyst and / or regenerated catalyst.

[0124] The hydroconversion process according to the invention comprises a step ii. of withdrawing spent hydroconversion catalyst and adding fresh hydroconversion catalyst from a storage enclosure 20 for fresh catalyst and / or hydroconversion catalyst regenerated according to the regeneration process according to the invention within said reaction section 40.

[0125] The said hydroconversion reactor(s) are equipped with a catalyst top-up and withdrawal system.

[0126] Regularly withdrawing used catalyst and adding fresh catalyst ensures that the quality of catalyst in the reactor is substantially constant.

[0127] In one embodiment, it is possible to withdraw spent catalyst from one reactor and supply regenerated catalyst to another reactor. In this case, the spent catalyst is typically withdrawn from the first reactor and the fresh and / or regenerated catalyst added to the last or penultimate hydroconversion reactor.

[0128] Preferably, the spent catalyst may be withdrawn from each of the reactors or from one or more of the reactors, in particular from the first reactor and / or possibly from the second. Depending on the units, it is also possible to withdraw spent catalyst from one of the reactors and then add it to another reactor.

[0129] In one embodiment, the regenerated catalyst may be added to each of the reactors or to one or more of the reactors.

[0130] In one embodiment, the steps of withdrawing spent hydroconversion catalyst and adding fresh hydroconversion catalyst and / or regenerated hydroconversion catalyst are carried out by a single device that can be pressurized and depressurized 30. In this embodiment, the single device is a catalyst loading and / or unloading pot, called a “High Pressure” pot or HP pot 30 because it can operate at the pressure of the hydroconversion reactor(s), and has the possibility of being in fluid connection with each of the reactors. This equipment allows the transfer of catalyst between the different pieces of equipment.

[0131] In one embodiment, the steps of withdrawing spent hydroconversion catalyst and adding fresh hydroconversion catalyst and / or regenerated hydroconversion catalyst are carried out by liquid phase conveying. Preferably, the liquid used is a hydrocarbon heavy enough not to vaporize significantly during conveying. Typically, the liquid used is a cut with a boiling range between 300 and 550°C, for example a vacuum distillate type hydrocarbon cut.

[0132] In one embodiment, the HP 30 pot carries out the conveyance of liquid phase hydroconversion catalyst to the various units. The HP 30 pot is used both to add fresh catalyst or regenerated catalyst to the reactor, and to withdraw catalyst from the reactor for regeneration or disposal if it is too loaded with metals.

[0133] The use of a single device to link the different catalyst storage units and capacities allows, firstly, to considerably reduce the costs linked to the process, such a device being expensive, but also allows to simplify the process with a single conveying device well integrated into an overall hydroconversion process with in situ catalyst regeneration.

[0134] In one embodiment, the HP pot 30 is equipped with a level measurement making it possible to measure the quantities, preferably the volumes of hydroconversion catalyst, added or withdrawn from the reaction zone.

[0135] In one embodiment, the HP pot 30 is in fluid connection with a storage enclosure 60 which contains the spent hydroconversion catalyst to be sent for regeneration.

[0136] In one embodiment, the HP 30 pot is in fluid connection with a “Low Pressure” pot called BP 50 pot which allows the storage of the used catalyst to be eliminated.

[0137] Typically, when catalyst is withdrawn from the reaction zone 40 for disposal or regeneration, the spent catalyst is transferred from the reaction section to the HP pot 30, which is then pressurized. The HP pot 30 is then depressurized and the catalyst is transferred to the LP pot 50 or the storage enclosure 60. The storage enclosure 60 makes it possible to store a sufficient quantity of catalyst to decouple the frequency and duration of the regeneration cycles from the frequency and quantities of catalyst withdrawn.

[0138] In one embodiment, the storage enclosure 60 then supplies a loading pot 70. The storage enclosure 60, or more preferably the loading pot 70, then supplies the regeneration device 100.

[0139] In one embodiment, the storage enclosure 60 is equipped with a device for measuring the quantities of catalyst.

[0140] In one embodiment, the HP pot 30 is fluidically connected to a storage enclosure 80 which contains regenerated hydroconversion catalyst.

[0141] In one embodiment, the HP 30 pot is in fluid connection with a “Low Pressure” pot called BP 20 pot which contains fresh catalyst.

[0142] Typically, when adding fresh catalyst, the desired amount of fresh catalyst is transferred from the first LP pot 20 to the low pressure HP pot 30. Then, the pressure of the HP pot 30 is increased until it reaches a pressure sufficient to transfer the catalyst from the HP pot 30 to the reaction zone 40.

[0143] In one embodiment, the HP 30 pot is remotely controlled by an operator.

[0144] In a preferred embodiment, the HP pot 30 is sized to accommodate the daily addition of the same required amount of fresh or regenerated catalyst, with the operator choosing to add fresh or regenerated catalyst depending on the metal content of the feedstock.

[0145] The hydroconversion process according to the invention thus allows great flexibility to the operator who, with the regeneration process integrated into the catalyst addition and withdrawal system, can treat feedstocks with very variable metal contents while keeping the content of coke and metals deposited on the catalyst in the hydroconversion reactors substantially constant.

[0146] The method according to the invention also makes it possible to flexibly process feedstocks of variable compositions, in particular with variable metal contents, the operator having the possibility of replacing the catalyst withdrawn from the reaction zone 40 with fresh catalyst or regenerated catalyst according to his needs. It is possible to keep the content of coke and metals deposited on the catalyst substantially constant in the hydroconversion reactors. In other words, in the method according to the invention, the metal content on the catalyst is decoupled from the coke content, since the operator can control

[0147] - on the one hand, the addition of fresh catalyst (containing neither metals nor coke)

[0148] - and on the other hand, the addition of regenerated catalyst (not containing coke but metals from hydrocarbon feedstocks).

[0149] The methods according to the invention thus allow the operator to limit the addition of fresh catalyst to loads containing few metals while maintaining controlled coke contents deposited on the catalyst.

[0150] System

[0151] The present invention also relates to a system comprising:

[0152] - a reaction section 40 comprising a hydroconversion reactor operating in an ebullated bed or in a moving bed;

[0153] - a regeneration section comprising a regeneration device 100;

[0154] - means for transferring hydroconversion catalyst between said reaction sections 40 and regeneration comprising at least one fluid connection;

[0155] - means for loading said regeneration device 100 into a fluidized bed or into a moving bed.

[0156] In one embodiment, the regeneration device of the system according to the invention comprises:

[0157] - a first enclosure 100 arranged around a vertical axis comprising in its upper part a regeneration gas inlet opening 14 and an inlet opening for the spent catalyst 9, said first enclosure 100 comprising in its lower part a regeneration gas outlet opening 15 and an outlet opening for the regenerated catalyst 10;

[0158] - a second enclosure 107, concentric with the first enclosure 100) and arranged inside the latter so as to form a space between said first enclosure 100 and said second enclosure 107, said second enclosure being capable of containing a bed of spent catalyst grains to be regenerated and comprises a sealed upper wall 114, side walls 105 porous over at least part of their height, the porosity of said side walls 105 being adapted to allow the flow of regeneration gases, and a lower wall 11 1, said second enclosure 107 being in fluid connection with the inlet opening of the spent catalyst 9 and the outlet opening of the regenerated catalyst 10.

[0159] - a third enclosure forming a central conduit 109 concentric with the second enclosure 107 passing through said second enclosure 107 and the first enclosure 100, said third enclosure 109 being porous over all parts of its side walls 108 contained in said second enclosure 107 for the evacuation of the regeneration gases, said third enclosure 109 being in fluid connection with the regeneration gas outlet opening 15.

[0160] "Watertight" means that it does not allow gases, liquids or solids to pass through.

[0161] "Regeneration gas" means drying, inerting and combustion gases.

[0162] The term "upper part of an enclosure" means the head of the first enclosure, generally hemispherical or elliptical, as well as the upper 15% of the shell.

[0163] The term "lower part of an enclosure" means the bottom of the capacity, generally hemispherical or elliptical, as well as the lower 15% of the shell.

[0164] In one embodiment, the regeneration device of the system according to the invention is loaded with hydroconversion catalyst within its second enclosure 107.

[0165] In one embodiment, the regeneration device of the system according to the invention comprises a partition 106 arranged in the space between the first enclosure 100 and the second enclosure 107 supporting the side walls 105 of said second enclosure 107 and separating in a sealed manner said space between the first enclosure 100 and the second enclosure 107 into a first empty upper zone 103; 104 and a second empty lower zone 112, and the first enclosure 100 comprises in its lower part an opening 101 for the introduction and the exit of a fluidization liquid in said second empty lower zone 112, and the lower wall 111 of the second enclosure 107 is porous to allow the flow of said fluidization liquid in said second enclosure 107.

[0166] Typically, the partition 106 may be a generally flat support ring a few centimeters wide which is welded into the lower part of the internal face of the first enclosure 100 and on which the second enclosure 107 rests. It serves as a support for the second enclosure 107 and provides a sealed separation of the space located between the first enclosure 100 and the second enclosure 107 into two separate zones. A conical-shaped collar may also be used.

[0167] Porous walls that allow fluids (gas and liquids) to be well distributed can be made up, by way of non-limiting example, of perforated plates, grids assembled into strips, sintered metal sheets. Modular stacks of objects made up of porous walls and forming a porous wall by assembly are also conceivable.

[0168] The largest pore size of the lower wall of the second enclosure 11 1 is smaller than the diameter of the catalyst grains in order to properly confine the bed of catalyst grains. The pore size of the lower porous wall of the second enclosure 1 11 allows the passage of the fluidizing liquid.

[0169] The largest pore size of the porous portions of the side walls of the second enclosure 105 and the side walls of the third enclosure 108 is smaller than the diameter of the catalyst grains in order to properly confine the bed of catalyst grains. The pore size of the porous portions of the side walls of the second enclosure 105 and the 108 allows the passage of regeneration gases.

[0170] The porous parts of the side walls of the second enclosure 105, of the lower wall of the second enclosure 11 1 and of the parts of the side walls 108 of the third enclosure contained in said second enclosure are advantageously sized to obtain a good distribution of the fluids over the different passage sections of the regeneration device.

[0171] The pressure drop offered by these porous walls is sufficient to allow the fluids to be distributed over the passage section.

[0172] The pressure losses during the passage of gases radially in the granular bed are preferably between 1 kPa and 100 kPa, preferably between 10 kPa and 50 kPa.

[0173] The pressure drop through the porous portions of the side walls of the second enclosure 105 and the portions of the side walls 108 of the third enclosure contained in said second enclosure is preferably between 1 kPa and 100 kPa, preferably between 10 kPa and 50 kPa. The pressure drop through the porous lower wall 11 1 of the second enclosure is preferably between 1 and 100 kPa, preferably between 10 kPa and 50 kPa.

[0174] To promote the distribution of the fluidization liquid through the lower porous wall 11 1 of the second enclosure, its unit pressure drop (under similar conditions and for a similar passage section) is preferably at least equal to the unit pressure drop of the porous parts of the side walls of the second enclosure 105 or of the parts of the side walls 108 of the third enclosure contained in said second enclosure.

[0175] The pressure loss of a porous wall is the pressure difference between the two enclosures it separates; it depends on the flow rate treated and the porosity of the walls.

[0176] In one embodiment, the first enclosure 100 of the regeneration device of the system according to the invention comprises in its upper part an opening 102 for the evacuation of excess fluidization liquid, said opening 102 being in fluid connection with the second enclosure 107.

[0177] In one embodiment, the regeneration device of the system according to the invention comprises a deflector 110 installed in the second enclosure 107 above the third enclosure 109 and below the inlet opening of the spent catalyst 9.

[0178] In one embodiment, the regeneration device of the system according to the invention comprises several inlet openings for the catalyst 9. They can be positioned centrally and / or peripherally in the upper part of the first enclosure 100. This variant can be implemented when the regeneration device is large.

[0179] In one embodiment, the regeneration device of the system according to the invention comprises one or more plates 113 to obstruct the flow of gases, said plates being arranged concentrically between the side walls of the second enclosure 105 and the parts of the side walls 108 of the third enclosure contained in said second enclosure 107. The lower part of said plate(s) 113 is preferably arranged at the top of the porous parts of the side walls of the second enclosure 105 and the porous parts of the side walls 108 of the third enclosure contained in said second enclosure 107.

[0180] In one embodiment, the lower wall of the second enclosure 111 of the regeneration device of the system according to the invention has the shape of a cone pointing towards the bottom of the device. In this embodiment, the lower part of the second enclosure 111 may be inclined at an angle of between 2 and 25°, preferably between 10° and 20° relative to the horizontal axis of the collar 106.

[0181] In one embodiment, the device of the system according to the invention comprises several outlet openings for the regenerated catalyst 10. They can be positioned centrally and / or peripherally in the lower part of the first enclosure 100. This variant can be implemented when the regeneration device is large.

[0182] EXAMPLE

[0183] An ebullated bed hydroconversion process is considered which treats a feed consisting of a mixture of atmospheric residues and vacuum residues, characterized by a density at 15°C of 0.995 kg / m 3 The feed rate in the unit is 11650 BPD (barrels per day).

[0184] This is a unit equipped with a single hydroconversion reactor with a catalyst inventory of approximately 140 t.

[0185] The treated feedstock has a metal content (Ni+V) of 55 ppm. The aim is to control the metal content on the catalyst at around 15%, while maintaining the average catalyst residence time between 20 and 40 days in order to limit the coke content deposited on the catalyst, which generally varies between 10 and 50% depending on the operating conditions. Under these conditions, the refiner adopts a fresh catalyst replacement rate of 0.35 kg / t of feedstock, which corresponds to a fresh catalyst addition of 0.70 t / d. This then allows the refiner to control the metal content deposited on the catalyst at around 15.3%. But with this replacement rate, the average catalyst residence time in the unit, corresponding to the inventory renewal time, is around 200 days, a very high value, linked to the fact that the metal content of the feedstock, close to 55 ppm, is low compared to the metal contents usually treated in this type of process.

[0186] In order to limit the coke content on the catalyst, it was decided to set up a regeneration of the catalyst by withdrawing the catalyst from the reactor to send it to a regeneration device according to the invention where the coke is burned.

[0187] The objective is to reduce the coke content on the catalyst by 15% compared to the initial content. To achieve this objective, it is necessary to withdraw approximately 8 times the amount of fresh catalyst added to the unit. This will ensure that the coke content level on the catalyst present in the hydroconversion reactor is substantially constant so that the reaction can proceed with optimal conversion yields. The regenerated catalyst, free of the majority of the coke deposited during hydroconversion, recovers most of its catalytic activity, allowing the desulfurization and demetallization of the hydroconverted hydrocarbons. The reintroduction of the regenerated catalyst therefore strengthens the catalytic activity of the reaction zone.

[0188] The addition and withdrawal cycles are therefore modified as follows. The initial management consisting of adding daily around 0.70 t of fresh catalyst every day and withdrawing the same volume of catalyst from the reactor is replaced by the following cyclic procedure: on the first day, 6.3 t of fresh catalyst are added (9 times 0.7 t) and the same equivalent volume V is withdrawn, which is sent for reprocessing outside the unit. The following 8 days, the same volume V of catalyst is withdrawn, which is sent to regeneration to burn the coke, and the same volume V of catalyst, which has already undergone regeneration, is introduced into the reactor.

[0189] It should be noted that the density of the withdrawn catalyst is different from the density of the fresh catalyst due to the deposits of material on the catalyst in the reactor. In the present case, it was observed that the bulk density of the catalyst leaving the reactor is higher than the density of the fresh catalyst, hence the volume management of catalyst withdrawals to allow a constant inventory to be maintained.

[0190] This procedure allows to eliminate part of the coke formed, and also to reduce the average residence time of the fresh and regenerated catalyst to a value close to 22 days. We then observe that the average coke content deposited on the catalyst withdrawn from the reactor is 0.85 times the coke content that would be observed when the regeneration is not working by adding only 6.3 t of fresh catalyst once every nine days.

[0191] The catalyst that is withdrawn for regeneration is stored in intermediate buffer tanks to then be loaded into the regeneration reactor sequentially. The time required to carry out a regeneration cycle of a batch being around 4 days, the regeneration is dimensioned to allow regeneration 5 times the volume V withdrawn daily, corresponding to a mass of catalyst close to 50t. The regeneration is implemented in the regeneration device according to the invention. After transport, loading and drying the catalyst is regenerated by a gas stream consisting of an air flow and recycled flue gases. In order to limit combustion, the O2 content in the incoming gas stream is kept below 1%. Under these conditions, the temperature gradient remains below 35°C between the inlet and the outlet of the bed.To achieve these conditions, the recycled flue gas flow rate corresponds to 69 times the fresh air flow rate and the gas flow rate feeding the reactor during regeneration is approximately 203 t / h, this flow rate including the recycled flue gas flow rate. Under these conditions, the combustion phase of regeneration lasts approximately 48 hours and is carried out by gradually increasing the gas inlet temperature from 275 to 450°C without ever exceeding the 35°C gas temperature difference between the inlet and outlet. The remaining 48 hours of the regeneration cycle correspond to the time required to carry out the other operations of transport, loading, drying, purging, and unloading.

[0192] The radial reactor for carrying out the regeneration has the following characteristics. The granular bed is arranged around the central conduit 109 with a diameter of 300 mm. The radial reactor has an internal diameter of 3281 mm, and the thickness of the catalyst grain bed is 863 mm between the porous walls 105 and 108. The height of the catalyst grain bed traversed radially by the gas is 7.42 m. An additional height of 1.2 m of catalyst is maintained above the catalyst bed traversed radially by the gas (above the top of the openings in the porous walls 105 and 108). A space for absorbing a volume expansion of the bed of 25% is provided above the granular bed in the radial space.

[0193] In order to fluidize the catalyst grain bed during loading and unloading, a flow of diesel fuel at 50°C is introduced. Under these conditions, the minimum fluidization velocity of the catalyst being 0.62 cm / s, a superficial velocity of 1.25 cm / s is applied in the annular space, which limits the expansion of the bed to around 10%. The flow rate of diesel fuel introduced through the opening 101 and necessary to ensure good fluidization of the catalyst is therefore 264 m 3 / h during loading and unloading.

Claims

Demands 1. A process for the in situ regeneration of a spent hydroconversion catalyst comprising the following steps: a) transferring the spent hydroconversion catalyst between a reaction section (40) comprising a hydroconversion reactor operating in a bubbling bed or moving bed configuration, preferably operating in a bubbling bed configuration, and a regeneration section comprising a regeneration device (100); b) loading the regeneration device (100) with the spent hydroconversion catalyst; c) regenerating the spent hydroconversion catalyst within the regeneration device (100) and obtaining a regenerated hydroconversion catalyst; d) unloading the regenerated hydroconversion catalyst from the regeneration device (100); e) transferring the regenerated hydroconversion catalyst between the regeneration section and the reaction section (40);said reaction section (40) and regeneration section being connected to each other by at least one fluidic connection allowing the transfer of the spent hydroconversion catalyst and the regenerated hydroconversion catalyst.

2. Regeneration method according to claim 1 wherein the regeneration section comprises a loading pot (70) containing the spent hydroconversion catalyst awaiting regeneration, and the step of loading the regeneration device (100) with the spent hydroconversion catalyst comprises a step of transferring said spent hydroconversion catalyst between said loading pot (70) and said regeneration device (100).

3. Regeneration process according to any one of the preceding claims wherein the step of loading the regeneration device (100) with the spent hydroconversion catalyst is carried out in a fluidized bed with a fluidizing liquid.

4. Regeneration process according to claim 3 further comprising a step of draining the fluidizing liquid and a step of drying the spent hydroconversion catalyst prior to the regeneration step of said spent hydroconversion catalyst.

5. A regeneration process according to any one of the preceding claims, wherein the regeneration comprises a step of combustion of the coke and sulfur compounds of the spent hydroconversion catalyst, implemented with a gas stream comprising oxygen passing through said spent hydroconversion catalyst radially within the regeneration device (100).

6. A regeneration method according to any one of the preceding claims, wherein the regeneration section further comprises a storage vessel for the regenerated hydroconversion catalyst (80) and the step of unloading the regenerated hydroconversion catalyst from the regeneration device (100) comprises a step of transferring said regenerated hydroconversion catalyst between said regeneration device (100) and said storage vessel (80).

7. Hydroconversion process comprising the following steps: I. a hydroconversion step of a hydrocarbon feedstock having an initial boiling point of at least 300°C implemented in a reaction section (40) comprising a reactor operating in a bubbling bed or moving bed in the presence of a hydroconversion catalyst and hydrogen; II. a step of drawing off spent hydroconversion catalyst and adding fresh hydroconversion catalyst from a storage vessel (20) of fresh catalyst and hydroconversion catalyst regenerated according to the regeneration process according to any one of claims 1 to 6 within said reaction section (40).

8. Hydroconversion process according to the preceding claim wherein the steps of removing spent hydroconversion catalyst and adding fresh hydroconversion catalyst and regenerated hydroconversion catalyst are carried out by conveying in liquid phase.

9. Hydroconversion process according to claim 7 or 8 wherein the steps of removing spent hydroconversion catalyst and adding fresh hydroconversion catalyst and / or regenerated hydroconversion catalyst are carried out by a single device that can be pressurized and depressurized (30).

10. System comprising: - a reaction section (40) comprising a hydroconversion reactor operating in a bubbling bed or moving bed; - a regeneration section comprising a regeneration device (100); - means for transferring hydroconversion catalyst between said reaction (40) and regeneration sections comprising at least one fluidic connection; - means of loading said regeneration device (100) in a fluidized bed or in a moving bed.

11. System according to claim 10, wherein the regeneration device comprises: - a first enclosure (100) arranged around a vertical axis comprising in its upper part an inlet opening for regeneration gas (14) and an inlet opening for the spent catalyst (9), said first enclosure (100) comprising in its lower part an outlet opening for regeneration gas (15) and an outlet opening for the regenerated catalyst (10); - a second enclosure (107), concentric with the first enclosure (100) and arranged inside it so as to form a space between said first enclosure (100) and said second enclosure (107), said second enclosure being suitable for containing a bed of spent catalyst grains to be regenerated and comprising a sealed upper wall (114), side walls (105) porous over at least part of their height, the porosity of said side walls (105) being adapted to allow the flow of regeneration gases, and a lower wall (111), said second enclosure (107) being in fluidic connection with the inlet opening of the spent catalyst (9) and the outlet opening of the regenerated catalyst (10). - a third enclosure forming a central conduit (109) concentric to the second enclosure (107) passing through said second enclosure (107) and the first enclosure (100), said third enclosure (109) being porous over all parts of its lateral walls (108) contained in said second enclosure (107) for the evacuation of regeneration gases, said third enclosure (109) being in fluidic connection with the regeneration gas outlet opening (15).

12. System according to claim 11, wherein the regeneration device comprises a partition (106) disposed in the space between the first enclosure (100) and the second enclosure (107) supporting the side walls (105) of said second enclosure (107) and sealing said space between the first enclosure (100) and the second enclosure (107) in a first upper empty zone (103;104) and a second lower empty zone (112), and the first enclosure (100) includes in its lower part an opening (101) for the introduction and exit of a fluidizing liquid into said second lower empty zone (112), and the lower wall (111) of the second enclosure (107) is porous to allow the flow of said fluidizing liquid into said second enclosure (107).

13. A system according to claim 12, wherein the upper part of the first chamber (100) of the regeneration device comprises an opening (102) for the discharge of excess fluidizing fluid, said opening (102) being in fluidic connection with the second chamber (107).

14. A system according to any one of claims 11 to 13, wherein the regeneration device comprises a deflector (110) installed in the second chamber (107) above the third chamber (109) and below the inlet opening of the spent catalyst (9).

15. System according to any one of claims 11 to 14, wherein the regeneration device comprises one or more plates (113) for obstructing the flow of gases, said plates being arranged concentrically between the side walls of the second enclosure (105) and the portions of the side walls (108) of the third enclosure contained in said second enclosure (107).

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